Mechanical respirator



June 2, 1942. F. R. MAUTZ ETAL 2,284,964

K MECHANICAL RESPIRATOR Filed 4July 2e, 1940 l o pecially Patented June 2, 1942 oFFlcl-L f I Frederick a. Mam and ons J. small, cleveland Heights, 0h10, assignors to Air Reduction Comf pany, Incorporated, New York, N. Y., a corporation ,of New York Application July 2s, 1940, serial No. 347,814

- This invention relatesto apparatus for maintainingvartificial pulmonary ventilation, and more` particularly to a mechanical respirator esadapted for use during surgical operatlons.` o Occasionally during surgical operations there may occur serious respiratory or cardiac failure. Articial pulmonary ventilation by mechanical .means has proved very helpful in such cases. In

thoracic'surgery, particularly in the presence of an` open pneumothorax,`the desirability of assisting natural respiration or maintaining full jartiilcial respirationI has been established, and.

it is among the objects of our present invention to provide an improved mechanical respirator which may be used in 'associationwith the usual closed system anaesthetizing equipment.

Other objects of ouroinvention include: the provision of a mechanical respirator whichcan vinstantaneously be placed in operation when the occasion demands but 'which will not interfere with the patients natural respiration at, other times; the provision. in a mechanical respirator,

of means for accurately and promptly controlling the rate of respiration; thev provision in a mechanical respirator of means for accurately and promptly controlling the maximum pressure applied tothe patient's lungs; the provision of a mechanical respirator which canhe attached at the point where the breathing bag is normally securedin an anaesthetizing machine and which is always ready for instant use; the provision i of an extremely simple respirator having a minimum of moving parts and which may be operated entirely by compressed air from any suitable supply: and the provision of a respirating apparatus for operating rooms which will establish and maintain any desired rate and-depth of respiration for any desired length of time and which may be employed to facilitate an exchange of voxygen or anaesthetizlng agents between the of respiratory depression.

' machine and the patients` alveoli during periods The above and other objects of our invention will appear more fully from the following description of one embodiment thereof, reference being `had to the accompanying drawing which 1o claims. (c1. 12s-'191) Figure3 is a plan viewlof the apparatus shown in Figure 2, taken on line 3,-3 of Figure 2.

Figure 4 is an enlarged vertical cross-sectional viewthrough the "on and on and manual operation control valve, taken ure 3. Y.

Figure 5 is a horizontal cross-sectional view taken substantially on line 5-5 of Figure 4.

In Figure l our respirator is illustrated as attached t'o one type of `closed system anaesthetizing machine-in which the usual face mask, which tightlyv covers the patients nose and mouth, is shown at I. .A soda-lime canister 2 isemployed on line 4-4 of Figin well known manner forl removing carbon dioxide. A exible supplytube '3 leads from the canister `2 to the mask I, and a ilexible return tube 4 leads from the mask I back to the canister 2. Suitable check valves 5 and 6 are inserted inthe conduits 3 and! adjacent the canister 2 so that, as the patient inhales, `air flows tothe mask vI through the pipe 3, but cannot be drawn into the pipe. 4 because of the check valve 6.

. During exhalation air ilows through the pipe 4 illustrates our improved respirator apparatus in more or less diagrammatic form, and in which- Figure 1 is a diagrammatic layout of our improvedrespirator attachedto an anaesthetizing machine.

Figure 2 is an enlarged side elevation of our respirator. v

into the canister 2, but is preventedfrom ilowing through the pipe 3 into the canister 2 by the check valve 5. A tank of oxygen or anaesthetizing gas is shown at 1 connected to the inlet pipe 3 through a connecting conduit il in which is inserted a pressure regulating valve 9. It ls understood that the above describes, in very simple form, the general arrangement of an anaesthetizing machine and it will be further understood that the machine may include a plurality of 'tanks similar to the tank 'I containing compressed anaesthetizing gases, etc., to be suppliedl to the patient. v

A pressure gauge I0 indicates the pressure in the conduit 3being supplied to the patient.- By

observing this gauge, the operator of the appa-, ratus can tell the-exact maximum pressure being appliedl to the patients lungs when therespirator is in operation. j

A exibleconduit II extends from the bottom Aof the soda-lime canister 2 to the respirator unit which is indicated at R in Figure 1.

' Referring now particularly tol Figure 2, lit'will be observed that the conduit II connects directly to the iiexible rubber -bag I 2' which is disposed in a cylindrical vessel, preferably having a glass or other transparent side wall I3. The hose Il is provided with an air-tight connectionthrough Athe top I4 of .the lcylindrical pressure vessel.

This connection is preferably made by any suitable quickly detachable means so ,that the rubber bag I2 can readily be withdrawn from the qwhich may be desired to be cylindrical chamber and replaced when desired. The cylindrical wall I3, the top plate Il and the bottom plate I5 provide an air tight chamber in which the bag I2 is disposed. When therespirator is not operating and the apparatus of Figure 1 is being used merely as an anaesthetizing machine, the bag I2 performs the function of the usual breathing bag and the bag contracts and expands in the usual manner in accordance with the patients respirations.

, In order to provide means for artificial respiration, we supply air under pressure to the pipe I6. In the illustrated'form of our invention, an

air pressure regulating valve is. shown at I1 and a compressed supply air line at Il, but it will be understood that in instances where air under` suitable standard pressure is available, the pres-` sure regulating valve I'I may be eliminated.

The pipe I8 leads to the valve housing I9 and thence through a pipe 20 directly into the interior of the pressure chamber. At the bottom of the pressure chamber isa poppet valve 2i,

a,as4,oc4

the top-plate u, a spring s1 is provided which exerts a lifting force against the underside of the operating knob 34.

In explaining the preferred use of our improved respirator, it will be assumed that the mask I is applied to and held in position over the patients nose and mouth. vWhen an operation is started compressed air is applied through the pipes I8 and 20 and the control valve 38 in pipe 20 is opened.- Such supply of air is maintained at a pressure in excess of the greatest pressure that is ever desired to be-applied to the patient, and the motorspeed control valve I9 is adjusted by turning the knob 2l to cause the poppet valve 2I to be lifted oil of its seat and reseated'at the proper rate to give the desired number of respirations per minute.`

Assuming that the patienthas -been anaesthetized and is breathing normally without need ol openingthrough the coinciding slots and 36- shown in closedposition in Figure l and in open position in Figure 21., This valve controls an opening from the interior of the respirator pressure chamber directly to the atmosphere and is adapted to be opened and closed periodically by means of a motor 22. As illustrated, this motor 'is of the fluid pressure actuated type and 4its shaft carries a cam 23 which engages the head 26 of ythe plunger 25 which carries-the poppet valve 2i at its upper end.l Thus, as the motor 22 operates, the cam 23 will alternately lift the. valve 2i oil of its seat, opening the pressure chber within the cylindrical wall I3 to the atmosphere, and permit the valve 2i to close, shutting o@ the pressure chamber from the atmosphere. The valve housing I9 contains a regulating valve 1 which controls the flow of air through the pipe 2Std the motor 22.v This valve is operated by a rotatable knob 2l and the disc 2B is preferably graduated to indicate respirations per minute. By adjusting the knob 21, the pointer 2Q' will indicate the speed at which the motor 22 is operating and. as the dial 23 is calibrated in respirarate of action of the respirator. f

An adjustable pressure relief valve, of any suitable type such as a spring loaded puppet type safety valve, is indicated at 33 in Figure 3. The dial 3l of. this valve is graduated in eters of mercury and the control range oi.' the valve is set to cover the possible variations in pressure applied to the pa- A,tients lungs.

In Figures .4 and y5 we have illustrated in some detail a start and stop control valve which is I also adapted to permit manual control of the ber which isformed with a conical recess in its underside to conformto and fit the upper conical surface oi -the member 32.

l slot extends for somewhat less than 180 in cir- `\cumference-andsncorresponding arcuate slot 3B is formed in the conical valve member32. In order normally to maintain the tapered conical valve member 32 in engagement with its seat on artificial respiratiomthe valve 32 will be in open position as shown in Figures 4 and 5 with a 'clear and the holes in the protective cover plate 39. Under these circumstances the air which is'discharged into the pressure chamber through. pipe 20 will-'pass out freely through the valve 32 and substantially atmospheric pressure will be main- I :35 and 38 do not overlap. Under these circum tions per minute, will indicate to the operator the Anarcuate slot 35 extendsthrough the top plate Il. This which rate and value woul tained inside of the respirator-chamber. This will permit normal operation of the breathing bag which will contract and expand without undue resistance under the iniluence df the patients respiration.

During this time,

turn the valve 32, through its operating knob 34,:

into closed" position in which the apertures stances, the only outlet for air from the respirator chamber is through the poppet valve 3i. As

this valve intermittently opens and closes, it will `be seen that each time the valve 2i is closed.

cated in Figure 1, and gas forced through the canister 8 and pipe 3 into the patients lungs.

When the valve 2i is opened by the action of the,l

cam 23,- pressure within the respirator chamber will immediately drop toatmospheric and exhale.-

tion will be permitted through the piped and the canister 2 into the bag I2, causing it to innate'. Next, the'valve 2i closes, the pressure in the respirator chamber builds up to the value permitted by the control valve Se, and the has collapses. This cycle .continues as long as the yvalve 32 remains oil or closed but will immediately cease upon again turning the valve .32 into the open position shown in Figures 4 and 5. Preferably the motor 22 is permitted to' continue to 'operate throughout 'the period during which the respirator may possiblybe required, and thus the apparatus can instantaneously beplaced in actionby merely u u'ning-the singleivalv'e 32.

the motor 22 continues tooperate at the desired rate, for example I8 res- In some instances it may be desired to asist the-patients normal respiration. This' can-be accomplished by closing the valve I9 so thatthe motor 22 stops with the valve 2| closed. Then, with the valve 32 in closed position, i. e., withthe slots 35. and 36 out of alignment, the operator pushes on the knob34, depressing the conical valve 32 away from its seat and permitting air to escape through the opening 35 in the top of the respirator housing. This depression of the lvalve -32 will open the respirator chamber' to the atmosphere and permit expansion of the bag |2. By releasing the pressure` on the knob 34 the valve 32 will close, pressure will build up in the respirator chamber to the permitted. value, and gas will be supplied to the patients lungs. -By alternately manually depressing and releasingthe valve operating knob 34,. the respirator may be operated in any 'desired .time cycle, either regular or irregular, as 'required by the patient's ccndition. e

In some instances it may be desirable to .use positive intra pulmonary pressure,` forv example 6 mm. of mercury,and maintain this pressure with a minimum of fluctuation during the pulmonary cycle. This may'c'onvenie'ntly be accomplished by closing th'evalves 2|' and V .and setting the pressure regulating relief valve 3|) at 6 mm. of mercury. With this setting-of 4the valves the pressure determined by the valve r30' will be maintained substantially constant within the respirator chamber.

Thegauge II! indicates the pressure which is controlled -by the pressurerelief valve 30. -This gauge is preferably located as close as possible to the mask I in order that a true indication of the pressure applied to the patient may be obtained and the dial 3| of the adjustable pressure relief valve 30 is preferably calibrated to correspond to the readings of the gauge '|I). The gauge is largely provided as a 'safety feature to check the operation of the valve 30.

Although we have illustrated our respirator as connected directly to the soda-lime canister of an anaesthetizing machine, it will be understood that the tube II might be connected directly to a face mask and artificial respiration effected independently of the anaesthetizing equipment. Also, -our respirator may be connected into an anaesthetizing system at a point other than the bottom of the soda-lime canister. For example, it might be connected directly into the intake pipe 3 of the mask.

, tilation of the patients lungs without interfering with the simultaneous supply of oxygen or anaesthetic to the patient.

Although we have described the illustrated embodiment of our invention in considerable detail, it will be understood by those skilled in-the art that variations and modifications may be made in the type and arrangement of parts without departing from the spirit of our invention; We do not, therefore, wish to be limited to the specific form herein described, but claim as our invention all embodiments thereof coming within the scope of the appended claims. f

l. In a mechanical respirator, walls defining a closed chamber, a flexible container in said chamber, a conduit leading from said flexible container, a face mask connected to said conduit, means for supplying air under pressure to said chamber outside of said flexible container. and independent means for intermittently connecting said chamber to the atmosphere and closing said chamber fromV the atmosphere.

2. In a mechanical respirator, walls defining a closed chamber, a flexible4 container in said chamber, a conduit leading from said exible container, a face mask connected to said conduit, means for supplying air under pressure to said chamber outside of said flexible container, means for intermittently connecting said chamber to the atmosphere and closing said chamber from the atmosphere, and independent-manually operable valve means for opening or closing said chamber to and from the atmosphere.

chamber, a conduit leading from said flexible With our improved mechanical respirator, air

at a definite pressure is supplied continuously to the respirator chamber and the operation of the respirator is controlled by merely opening and closing an atmospheric connection to the respirator chamber. This requires a minimum of apparatus and only the most simple forms of valves. By our instantaneous on and off" valve V, the respirator can be put into action immediately as the motor 22 and valve 2| will normally be operated continuously during the course of an operation in which the respirator may possibly be needed. l

By providing means for adjusting, not only the rate of respiration, but also the pressure applied to the patient's lungs. an extremely sensitive and complete control is available. `When attached to an anaesthetizing machine the rubber bag I2 of our apparatus serves as a breathing bag during the ordinary maintenance of anaesthesia, and also as means for effecting mechanical vencontainer, a face mask connected to said conduit, means for supplying air under pressure to said chamber outside of said flexible container, means for intermittently connecting said chamber to the atmosphere and closing said chamberfrom the atmosphere, independent manually operable valve means for opening or closing said chamberV to and from the atmosphere, and an adjustable relief valve adapted to control the maximum pressure obtainable within said chamber.

4. In a mechanical respirator, walls defining a closed chamber, a flexible containerl in said chamber, a conduit leading from said exible container, a face mask connected to said conduit, means for supplying air under pressure to said chamber outside of said flexible container, valve means for 4connecting said chamber to the atmosphere and closing said chamber from the atmosphere, motor means for operating said valve means, independent manually operable means for opening or closing said chamber to lating the rate of operation of said motor means.

5. In apparatus of the type described,"anaes thetizing means including a face mask, a container for a carbon dioxide absorbing agent, a conduit fromsaid face mask to said container, a. flexiblebag, a conduit connecting said bag and said container, means for supplying a gas to said anaesthetizing means, a vessel enclosing said flexible bag, means for connecting a source of fluid pressure to said vessel, means for varying the pressure within said vessel in a repeating cycle by periodically opening a pressure relief valve on said vessel. and independent valve means for connecting said vessel to or closing said vessel off from the atmosphere.

6. In apparatus of the type described, anaesthebag, aconduit connecting said bag and said-container, means for supplying a gas to said anesthel tizing means, a vessel enclosing said'ilexiblebag, means for connecting ja source o f l fluid pressure to the interior of said vessel-outsidepi-said- .bag."

means for varying the-pressure within said vessel .ina repeating cycle'by'periodically' opening a pressure relief valve onsaid`ves sel, independent valve meansfor connectingfsaid'vessel-to or clos` adjustable relief valve means `for` controlling the 'maximum pressure which may. be established in said vessel..

v means including a face-mask, a -container -fora carbon dioxide absorbing agent, a conduit froxnsaid facemaskto said containena ilexible' means for controllingA said.,opening, Y i having a second opening throughajwall thereof,

and manually operable valve means for-.controlling said second-opening.

ing' Vsaid vessel'oi! from the atmosphere; fand 9. In a mechanical respirator, a vessel-,anexible'bag in said vessel a conduit leading from said `.bag throughfa v'vall of said vessel; a conduit con# -necting a source o! supply of air under-pres`sure' to the interior ofthe vesseloutside oisaid-bag.

saidvessel having an'foutletopening through a wall thereof. a. .checkvalve resiliently seated'over said outlet within saidr vessel. and means extending to the exterioro!- the .vessel forunseating said valve.

'1; m a mechanical respirator, a' vessel, unex;

nectinga source of supply-of airV under pressure -to the interior of said vessel outside. of said' bag, .said vessel having an outlet opening through' a wall thereof, mechanically periodically actuated ible bag in said vessel, a eonduitleadingfromsald bag through-a wall of said vessel, a conduit-convalve means for controlling saidopening, and

l0. In amechanlcal respirator, a. vessel, a iiexible baginsaidivessel, al conduit leading from said bag through awall of .said..vessel,'a source o'f supply of air under pressure, a conduit connecting said source to said vessel, said vessel having an [opening through la wall thereof,'manually operable valve means for controlling said opening. said valve means including a seat. a closure meinber adapted to engage said seat, said .opening in the vessel wall extending through said seatand said closure member having Van opening adapted-V .to be moved into and out of alignment with said vessel opening, resilient means for holding -said closure member against-said seat, and an operating member for said valve whereby said closure member 'may be moved' -away Vfrom -said seat against Vthe action of said resilient means.

FREDERICK n. oars Je.. SMITH.

'Patent No. 28h-5961!" CERTIFICATE oF coRREcTnIQN.'

June 2, 1924.2'. AFREDERICK R. mummia' im.v

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Signed ardfsealed his lhthdjy of Jil-Inl'. D; v 

